Potash cartridge for oxygen respirators and lifesaving apparatus



Patented July 30, 1940 FIC POTASH CARTRIDGE FOR OXYGEN RESPI- RATORS AND LIFESAVING APPARATUS Heinz Schmidt and Jan Jeiek, Usti nad Labem,

Czechoslovakia, assig'nors to Spolek Pro Chemickou A Hutni Vyrobu, Usti nad Labem, Aussig A. E., Czechoslovakia No Drawing. Application February 23, 1938, Se-

rial No. 192,182. In Czechoslovakia 1 Claim.

In oxygen respirators and lifesaving apparatus, such as is employed more particularly in mining and in fire fighting, so called potash cartridges are provided which are filled with caustic soda 5 and/or caustic potash and to which falls the task of absorbing the carbon dioxide from the spent respiratory air.

The activity of these fillings keeps up in use for only a short time since the caustic alkali,

1o usually present in granulated or lumpy form, be-

comes coated with a carbonate crust afterv a 4 short time, which prevents the respiration of air to be regenerated gaining access to the still un spent caustic alkali. This means only incomplete l6 utilisation of the filling and. premature passage g5 during use, which has the result that always fresh, still uncarbonated, portions of the caustic alkali can act on the respiratory air to be regenerated. Quite a few percent, fo example May 8,

12%, of such additions suflice to attain the desired eilect.

7 Example A hot liquid caustic soda melt is mixed with 2% of its weight of .solid aluminium sulphate and the melt homogenised whilst stirring until the sulphate is completely dissolved. The mass is thereupon allowed to set and is granulated in 'known way. Instead of aluminium sulphate, metallic aluminium or other metals, such as zinc, lead, cadmium and so forth, or compounds thereof, may also be used, alone or in admixture with one another.

As filling for potash cartridges the masses obtained in this way possess on an average a resistance time which is about 50% higher than that of products prepared from soda melts.

What we claim is:

A method of preparing caustic alkali for cartridges for use in respira ors and life saving apparatus, consisting in dissolving in a hot liquid caustic alkali bath 2% of its weight of aluminium sulphate, allowing the mass to set, and

granulating the set mass.

EEINZ SCHMIDT.

JAN JEZEK.

usual caustic 

